I really like this list made up by AvM(just follow the link). I know it is pretty long, and may seem daunting, but he has everything color coded for importance. Just start with the more important stuff and work your way down as you feel comfortable with it. But, remember, your mod list should really follow your personal preference, so just use this list as a basic guide.
Eventually the modding community for SH5 will put everything together into a super mod I am sure, but that is a good ways away.
Hope this helps
Link:
http://www.subsim.com/radioroom/show...&postcount=131